In the mechanical transmission of power, large open gear sets are frequently employed, particularly in plants having large mills, kilns and the like. Lubricants conventionally used for open gear sets generally possess good adhesive properties to assure that a film of lubricant is maintained on the contact surfaces of the gear teeth. In the usual case, to lubricate an open gear set, the lubricant is generally applied using a all-loss method.
At present, open gears are lubricated with heavy asphaltic lubricants which are applied continuously by a paddle wheel or periodically by a system known to those skilled in the art as a Farval system, usually once every 15 to 20 minutes. Although such systems are generally acceptable, a number of problems have surfaced in recent years. One such problem stems from the fact that most sprayed-on lubricants are diluted with a solvent. As may be appreciated, with today's heightened concern for the environment, the presence of such solvents necessitate that special handling procedures for waste lubricants be employed. From a lubrication standpoint, when premature evaporation of the solvent occurs, pumping problems are often encountered even before the lubricant is applied. Since presently employed open gear lubricants are all-loss materials, following their application, they become a hazardous waste material. Moreover, leaked or spilled open gear lubricants, due to their inherent tackiness, are difficult to clean up. In states where disposal is strictly regulated, the cost of proper disposal of used open gear lubricants may run in excess of $200,000, annually, for the average plant, and can be expected to increase in the future.
From a mechanical standpoint, much of the wear which occurs in open gear sets is caused by a combination of airborne abrasive dust and the present "feast-or-famine" method of periodic lubricant application. As can be appreciated by those skilled in the art, when lubricants are applied using a form of periodic application, the film so applied will usually vary from being somewhat excessive, just after application, to being somewhat inadequate, just prior to the next application.
Therefore what is needed is an open gear lubricating system which overcomes the aforementioned problems and, in particular, is acceptable to open gear builders, employs a lubricant which has recycle capability, negligible environmental impact, is cost effective, permits easy clean up, prevents gear wear and offers improved power transmission efficiency.